Pressure gauge



Patented July 13, 1926.

UNITED STATES PATENT OFFICE.

arena s. moron, or

roieono. Incontinence-rs,

nssmnon. no man roxnono com rm, P0113030, IABBAOEU BEMS, A CORPORATION 01! RABSAGRUBEMB.

ransom canon."

l |pllcoflon fled June 18, 1817, Serial llo. 174,608. Believed January 10, 1884.

This invention relates to gauges and in its more specific aspects to a pressure gauge of the t pe which measum pressures throufih the ductuations of a body of liquid suc a for example, as mercury.

My invention will best be understood by reference to the following descri tion of an illustrative embodiment that-coi taken in connection with the accompanying draw- 0 ings, wherein,-

' Fig.1 is a side elevation of an instrument embodying my invention partly broken awe.

Fig. 2 is a section on the line 2-2 of Fig.

6 1; and

Fig. 3 is a view on a larger scale of one of the buoyed "valves, partly broken away.

Referring to Fig. 1, the instrument shown comprises a. casing 5 containin any usual 0 or customary form of time me anism (not shown) adapted to rotate the dial 7 over which sweeps the pointer 9 carrying a. pen

11 adapted to record on the dial. The point:

er 9 is carried by a sleeve 13 which takes Ii motion through the clutch springs 15 from a shaft 17 which is adapted to be rotated by the ressure-responsive mechanism which shall next describe. The parts so for referred to may be of any usual form and do J not in themselves form a part of the present invention.

The instrument illustrated is adapted to record pressure conditions and in particular the algebraic sum of two diiferent pressures,

s by the fluctuations of a body of mercury or other fluid which may be isposed in two parallel and confluent columns.

Referring now to Fig. 2, I have herein shown a moron containing chamber or 1 well 19 at the si e of which rises 11 second chamber or well '21, conveniently longer and of smaller diameter than the well 19 and preferably merging, as shown, into a somewhat lar chamber 22. The'two wells are i connecte by the web 23 which may be formed of a section of tube having a plug welded therein. Commumcation between them is provided a conduit preferably of U-shaped form. erein a depending tube 1 25 is in communication with the well 19 and Ya similar de ending tube 27 with the well 21. A U-tu e of the tubes 25 and 27 and has terminal me be connected 29 connects the lower ends flanges secured to the ends of those tubes by couplings 30. 4

he mercury containing system described to the casing 5, as shown,

by ein secured to a housing 31 carried on thglfhajc i of the casing and surrounding the t The movement of the mercury in the well 19 is communicated to the shaft b means of u flout 33 adapted to rise and fafi with the mercury column. The float 33 conveniently has the form shown in Fig. 2, and at its upper surface has a conical end portion 35 for a purpose hereafter to be more fully described. The motion of the float is com municated to the shaft 17 by means of a crank 37 carried by the latter, and the link or pitman 39 pivoted to the crank depending therefrom and resting on the a conic recess which file over the conical end 35 of float 33 and forms therewith a swivelin joint permitting free movement of the float ut accurately transmitti vertical movement of the latter to the craiil arm 37. To guide the float and center it in the well I may conveniently adopt the construction illustrated in Fi 2. I have there shown a tube 4-1 extending from the bottom of the well 19, and the float 38 has a depending stem 43 which is guided in the tube convenientl by means of collars 45 having thin inner ges to engage the stem with minimum friction and provide a passe e or the mercury. In the side of the tube show a cook 47 in the form of a. small needle valve which permits drawing oil an excess of mercury when the mstrument is first filled therewith so as prop. erl to adjust the quantity within the same.

he pressures which it is desired to measure. are admitted to the two wells 19 and 21 to take effect in opposite senses on of liquid held thereb Herein the higher pressure is admitte to the housin '31 whence it passes through a tube 49 w ich referably as shown, has a blind end and ateral on ces 51, to well 19. These orifices discharge the flow of ressure fluid from the tube against the a jacent curved wall of the housing 31. If b chance any mercur is discharged into &a housing it will str' e the closed end of the tube 49 butfloat 38. The link Bflfipreferably has its and formed with rforated as shown to the body float 33 is rectilinear, whereas the movement of the crank arm 37 is an a ular movement. To compensate for the maccuracy of transmission due to this mechanical construction, the effective cross-section of the wells may be varied so that the displacement from one well to the other of a given volume of mercury will eflect at different times dilferent variations of level. The corresponding variable movement of the float is arran ed to give a regular movement of the era 37. I herein obtain this ell'ect by inserting in the well 21, which is itself of uniform bore, a member 61 of a cross-section varying along its length which has the efl'ect of varying the cflective section of the well. Herein this member 61 is formed of a Hat strip or her having at one end as mental threads permitting it to be secure in the threaded socket 63 at the base of the well. Since the bar is flat the circular o ening at the base of the well is not closed. '1 \c bar 61 has one straight ed e 65 and the opposite edge 67 is cut awn a ong a curve, the form of which is proper y determined to cil'ect the desired variation in the movement of the surface of the mercury column in the companion well 19. The form of the edge 67 is in practice determined empirically.

A member constructed as described can be convenient] calibrated for a given instrument by planing away the straight edge, so that it forms a very simple and advantageous correcting device.

I shall ncxt describe the mechanism by which the instrument is shielded against sudden excessive pressures and whereby I prevent the controlling fluid from being blown from the wells into other parts of the mechanism. Above the float 33 and conveniently as shown between the housing :31 and the well chamber 19 is provided a member 69 having an orifice or port therein presenting a seat adapted to cooperate with the conical end 35 of the float 33 to cut oil communication brtwcen the well 19 and the housin 31 when the float is raised to an extreme position somewhat higher than that illustrated in Fig. 2 of the drawings. The link 39 is arranged to extend through the port of the member 69- for support by the limit 33. It will thus be seen that if the surface of the mercury in the well 19 suddcnly' rises to an unusual degree through oom-1a sudden fluctuation of (pressure or otherwise, the float will be scale and prevent the discharge of any mercury into the housing 31 and that the operation of the instrument will temporarily be halted.

In conjunction with the mechanism just described, further means are provided for controlling the operation of the device when abnormal pressure is exerted on either column. Herein I have shown the ends of the U-tube 29 as formed with valve seats adapted to cooperate with valves 73 control ed by buoys 75 housed in the le s of the U formed by the tubes 25 and The valves ma conveniently take the form shown in ig. 3 the buoy 75 consistin of a hollow body 0 osed by a cap 77 and having a depending stem 79 carrying the valve roper 73 and another stem 81 adapted to guided in a erforahed collar 83 in the leg of the U. a buoys are normally submerged and the valves 73 are raised from their seats. v If the column of mercur sinkson one side so that it no longer ho is the buoy in elevated position, the corresponding valve will close and shut all communication between the two wells. Also if the column is subject to sudden fluctuation the buoy will be carried down so as to close the valve and prevent the mercur from blowing out of the instrument at t If! other side.

The buoy controlled valves are so designed that they are immediately released when the diflerential of pressure is within the limits for which the instrument is desi nod. If there is a sudden fluctuation the va ves will be swept along in the mercury current and close to prevent blowin of mercury from the instrument, but wil immediately be released when the abnormal conditions have terminated and consequently :1. record will alwa s be made on the chart 7 whenever the di erential pressure is within the limits of the chart. It will be understood that once a valve is seated it will be sub'ect directly to the pressures in the two we is and that the buoyancy of the body-75 will act in reinforcement to one of these pressures and in opposition to the other. As long then as the differential is in the opposite sense to and reater than the buoyant ell'cct the valve W1 1 remain seated but will lift as soon as the difierential falls in value below that ofiect. The buoys might go said to give the valves a predetermined hen air or other gas enters a column of mercury and escapes through the same, as may hop enter on er certain abnormal conditions, a bubble of air is frequently trapped beneath the body of mercury which rises as a unit. To prevent this segregated body or slug of mercury from being lown out of the instrument the well 21 is enlarged in the n in an instrument of this charmenus chamber 22 to efiorduflpportuni for the air bubble to esca prefer 1y means are provided for rocking up this slufi of mercury. I have herein shown a buille p ate member in the form of an inverted cup 85 of the some general cross sectional contour as the chamber 22 but somewhat smaller, suspended therein by means of a stem 87 secured to the cap 53. The cup 85 me have a. beveled edge as shown and its hot m is preferably coned, that is, it has its feces dis posed at a. diagonal as shown. The side walls of the cup adjacent the bottom are provided with lateral o nings 89 and herein the conical bottom we is are provided with *rooves 91 leading to these openings 89 and t ms providing downwardly and outwardly directing passages to the outside of the cup. Herein the inner diameter of the on is somewhat greater than the diameter the well 21 so that the cup extends completel over the open top or mouth of that w l where it joins the enlarged chamber 22, the cup being spaced as shown a slight distance above such top or mouth. When the slug of mercury rises it is partly broken up by the edges of the cup and further shattered b the bottom thereof and dischar in sma 1 particles by the openings 89 an allowed to gravitate back toward the well 21.

When it is desired temporarily to render the mechanism inoperative, for example, when the same is shlplped the well 19 may be isolated from the ousing and the body of mercury thereby be completely encased in the chamber provided therefor, this being effected by means of a manual control which I have provided for the valve constituted by the float 33 and the co -operating member 69. Longitudinally adjustable in the tube 41 is a member 93 threaded into the cap 95 which closes the lower end of the tube and movable by a hand wheel 97 Fig. 1). This member 93 is adapted, when adjusted upwardly from the position shown in Fig. 2, to engage the lower end of the stem 3 and press the float 33 upwardly to seat the same against the member 69, thus effectively sealing the well 19 and, since the float which actuates the pointer 9 is held immovable, rendering the mechanism temporarily inoperative. To close the well 21 the valve 5915 closed.

The end of the member 93 is preferably formed with a head 99 which co-operetes with a seat formed in a bushing 101 tightly screwed to the end of tube 41. A p ing 103 is placed between the bushing and the cap 95. When the mechanism is put out of operation screwing up stem 93 the pucking will provide against eaknge. When the instrument is in use, however, there maybe a strong presure on the joint. The stem is therefore preferably no adjusted that the head 99 will seat on the bushing 101 in the manner of a valve efiectually to prevent leakage of mercury.

To prevent strain on the shaft 17 during shipment of the instrument an arm 105 may be secured to the wall of the chamber in housing 31, said am having a notch adapted to receive the end of the pitman 39 when at its u permost position and to limit lateral vibration of the pitman and the flexible crank 37.

The operation of the device is as follows. Assuming the parts to be assembled, mercury 1s poured into the interior of the instrument through the hole which is closed by the pin 60. An excess mercury mu thereafter remove through the cock 4 until the pointer gives the proper reading. The instriunent may then be prepared for shipment by screwin down needle valve 59 an turning hand w eel 97 so that the rod 93 eng es stem 43 and presses the float against t e seat in member 69.

When the instrument is received, the tube 49 and pi e 57 are connected to sources of pressure, t a former being the high ressure and the latter the low pressure si e. The valve 59 is opened and the rod 93 screwed down until the enlargement 99 seats, sealing the lower end of tube 41. Fluid under ressure entering the tube 49 is discharge Iaterally against the wall of housing 31 through openings 51 and tends to depress the column of mercury in well 19 and to cause the float to sink. This tendency is resisted by the pressure of fluid entering through inlet orifice 57' and actin on the column of mercury in well 21. e algebraic sum of the pressures will determine the position of the float and consequently the ition of the pointer or hand 9 to whic motion is transmitted through link 39 and crank 37. The movement of the fluid for a given vertical distance in the well 21 will cause a varying rise or fall in the well 19, since part of the tube 21 is occupied by the displacement member 61 the size of which varies for different units of its height. This variation is designed to compensate for the action of the transmissionmechanism including the crank 37 which would not in itself elfect equal. movements of the pointer for equal movements of the float.

If the instrument is subjected to abnormal pressure tending to lift the float 33,111! valve will seat on the member 69 and revent discharge of mercury into the bonemg 31. Also, if there is a sudden fluctuation of pressure or if it rises or falls so as to go beyond the limits of the dial of the instrument, one or the other of the buoyed valves 73 will seat and revent any more mercury from passing om one well to another. I refer to the paragraph in this specification beginning "The buoy-controlled valves are so designed for a further [III description of their action. If a bubble of air is trapped in the mercury and tends to blow out a segregated body or slug of metal from the well 21. it will strike the diagonally disposed walls of the inverted cup 85 and will be broken thereby and disintegrated and directed downwardly through the openings 89 back to the well, while the air bubble escapes.

Having thus describedin detail the particulnr embodiment of m invention shown in the acoompanf'ing rowing, the feeturns thereof 'whici I claim as new and dosire to secure by Letters Patent I shall express in the following claims:

1. An instrument of the class described comprising a receptacle for a, pressure-sensitive fluid column, a float therein, an indi cator, and connections therebetwecn including a depending link having a substantially conical recess, and said flout having a projection received in said recess.

2. An instrument of the class described comprising a chamber adapted to receive a ressure-scnsitive fluid column, a flout there- 111, there being a. port to admit pressure to the column, the margin of which presents a seat, said float having a portion adapted to cooperate with said seat to close the ort, a tube opening to the bottom of said c nunber a stem on said float "uiderl in said tube, and a longitudinally lldJllStllble member in said tube having a portion cooperating with said stem to press the float against the seat independently of the fluid column.

3. An instrument of the class described comprising a chamber adapted to receive a pressure-sensitive fluid column, a float therein, there being a port to admit pressure to the column, the margin of which presents a seat, said float having a portion adapted to cooperate with said seat to close the port, a screw-threaded member beneath the float adjustable by rotation and adapted to engage sa'id float to press the same a ainst the seat independently of the fluid co umn, an indicator and connecting means between said indicator and float including a swivellin gioint whereby to permit movement of said out with said member Without strain on the connections.

4. An instrument, of the class described comprising a chamber adapted to receive a pressure-sensitive fluid column, a float therein, there being a ort to admit pressure to the column, said out having a conical portion adapted to enter said port and seat on the mar in thereof, on indicating device, and connections between the same and the float including a link having a recess adapted to receive and rest on said conical portion.

5. An instrument of the class described comprising a chamber adapted to receive a insure-sensitive fluid column, a float therein, there being a port to admit pressure to the column the margin of which presents a seat, said float having 5, portion adapted to cooperate with said seat to close the port, an indicating device, and connecting means between the same and the float extending throu h said port.

6. n instrument of the class described comprisin communicating wells for the reception o a fluid means to admit pressures to said wells, a float in one well a orted seat above said float which sent is a pted to cooperate with the float to close said well, and u tube openin from the well, said float hearing a depending stem guided in said in e.

7. An instrument of the class described comprisin communicating wells for the reception of a fluid means to admit pressures to said wells, 8. float in one well, a ported sent above said float ada ted to cooperate therewith to close said we] and a tube open' ing from the well, said float having a tie pending stem guided in said tube and a manu 1y adjustable member in said tube having a portion cooperating with said stem to press the float against the seat.

8, An instrument of the class described comprising communicating wells for the reception of a fluid, means to admit pressures to said wells, a float in one well, a ported seat above said float ado ted to cooperate therewith to close said wel and a tube opening from the well, said float having a depending stem guided in said tube, an indicator and connections therefrom comprising a linlc adapted to extend through the port of said scat and rest on the float.

9. An instrument of the class described comprising communicating wells for the reception of a fluid means to admit pressures to said wells, a float in one well, a ported scat above said float ado ted to cooperate therewith to close said wel and a tube open ing from the well said float having a depending stem guided in said tube, an indicutor, and connections between the indicator and float through the port of said seat.

10. An instrument of the class described comprising a chamber ado ted to receive a pressure-sensitive fluid co umn, an indicator, transmission means for controlling said indicator responsively to movement of the column, and a displacement member in said chamber comprising a solid bar havi straight edge and a curved edge providing a var ing section and on she of being plane oil along said straig t edge.

11. In an instrument 0 the class described 11. fluid containing well and means for varying the eflective section thereof comprising a. at bar having segmental threads at one end and a threaded socket in said well receiving said segmental threads.

12. vAn instrument of the class described having a well and means for breaking up one e slugs of fluid in the well, an inverted cup controlling the communication between said it therein having sloping exterior bottom chamber's. walls and lateral openings adjacent the bot- 2i. In an instrument of the class de tom. scribed, chambers for receivingfluid 001- 13. An instrument of the class described umna aving a connecting passage between having a well and means for breaking up them, normally submerged buoys for the 1 slugs of fluid in the well comprising an columns, valves carried thereb and valve inverted cup therein having lateral openseats cooperating with the va ves for rellngs adjacent the bottom thereof. atively isolating the chambers on abnormal 14. An Instrument of the class described resultant pressure of either column. I having a well and means for breaking up 22. In an instrument of the classZde- 75 slugs of fluid in the well comprising an inscribed, opposed wells to receive fluid cblver ed cup therein having dia onal bottom umns, an indicating float in o'newell, a walls and openings at the use of said valve seat coo crating with said float to walls. close the chamber when the float is abnor- 15. An instrument of the class described mally raised and means to limit fluctuation 9 having a well and meansfor breaking up of said columns in the opposite direction slugs of fluid therein comprising an incomprising a buo a valve carried t-hereb vented cup in said well having diagonal botand a valve seat cooperating with said valve.- tom walls, said walls having grooves open- 23. In an instrument of the class de-- ing through the sides of the cup. scribed, opposed wells to receive fluid 001- 35 16. In an instrument of the class de'- umns, an indicating float in one well,-a scribed having a well receiving a liquid valve seat coolperatmg with said float to column subject to opposed pressures, a battle close the chem er when the float is abnormember, ,means for supporting the same mall raised and a buoy controlled valve above the" normal level of the liquid in said for imiting fluid movement in the opposite well, said member havin an extended surdirection.

face presented transverse y thereto to pre- 24. A diflerential pressure instrument sent a shattering barrier to slugs of liquid havin a scale and an index, chamblown upwardly. bers i or confluent fluid columns, means to 7. In an instrument of the class do admit pressures to said columns and opscribed havin a well receivin a li uid positely acting valves controlling the comcolumn subject to pressure, a be e mem r, municaticn between said columns and biased means for sup orting the same above the to release at predetermined limits of diflernormal level 0 the liquid in said well, said ential pressure corresponding to extremes of member having an extended surface presaid scale. 1 0 sented transversely thereto to present a 25. A differential pressure instrument shattering barrier to slu of liquid blown having a scaleand an index, chambers for u wardly, the up er sur ace of said member confluent fluid columns, means to admit sl ping to drain ack to the well any liquid pressures to said columns and oppositely driven past the same and dropping on the acting valves controlling the communication 105 upper rtion thereof. between said columns and buoys tending to 1B. Iii an instrument of the class deunseat said valves and dos: ed to correscribcd having a well receiving a liquid spond to predetermineddimits of diflerencolumn subject to pressure and margin at trial pressure corresponding to extremes of its upper end in an enlarged chamber avsaid scale. ing' a port to admit fluid, a baflie member 26. In an instrument of the class deand means for sup orting the same in said scribed having chambers to receive confluent chamber above the fave] of the liquid in the fluid columns and means to admit pressures well and above the top of the well, said to said columns, means for determining a bafllo member' extending over the mouth limit of indication for said instrument comthereof but spaced from the wall of said rising a valve to interrlcilpt communication chamber. tween said columns an a buoy normally 19. In an instrument of the class detend' to unseat the valve. scribed, communicatin chambers for receiv- 27% gauge of the U tube type havmag a in fluid columns and valve means to shut valve seat in one of itsdegs, abnogapt Y v0 0 the communication between said chamheld submerged in them icatlng ind above here by the action of abnormal pressure on said seat and adapted to close thereon by either column. action of abnorma pressure.

20. In an instrument of the class de 28. A gauge of the U tubetype fl g I scribed, chambers for receiving fluid colnormally open check valve between the legs umns a U shaped conduit connecting said thereof comprising a valve seat and a norchambers, valve seats in said conduit and mally submerged valve responsive to the buoyed valves housed in either leg of the U velocity action of the indicating fluid under abnormal conditions to be carried thereby stem guided by said tube, a member enterin to its seat. said tube from the exterior and arrang ll 29. A gauge of the U tube type havi a. for adjustment against the stem to seat said valve sea in one of its legs, a buoyant va ve float, an enlar ement on said member and cooperahi with the seat and tending to a seat adaptc to coo rate with the enrise there rom, said valve being held norlargement to seal the tu h e mally submerged in the indicating fluid. 32. An instrument of the class described 80 30. In an instrument of the class decomprisin eomunicating wells for the rescribed a chamber to receive a pressure 5enceptlon 0 a fluid, means to admit pressures sitive fluid column, a float therein, there beto the Wells, a float in one well, a ported ing a port to admit pressure to said column seat above the float ada ted to cooperate the margin of which presents a. seat adapted therewith to close the we 1, a tube opening 85 to cooperate with said float, and means for from the well, said float having a depending moving said float against said seat includstem guided by said tube, a bushing at the ing a rod, a valve member on said rod and end of saidtube, a rod passing through said a seat to cooperate with said member. bushing, and adjustable against said stem 31. An instrument of the class described to seat the float, a packing for the rod and comprisi communicating wells for the rean enlargement on the rod ada ted to be caption o a fluid, means to admit pressures seated against the bushing inwar ly thereof to the wells, a float in one well, a ported to seal the tube. seat above the float ada ted to cooperate In testimony whereof, I have signed my therewith to close the we I, a tube opening name to this specification. from the well, said float having 9. depending EDGAR H. BRISTOL.

abnormal conditions to be carried thereby to its seat.

29. A gauge of the U tube type havin a valve seat in one of its legs, a buoyant va ve cooperatin with the seat and tending to rise there rom, said valve being held nor mally submerged in the indicating fluid.

30. In an instrument of the class described a chamber to receive a pressure sensitive fluid column, a float therein, there being a port to admit pressure to said column the margin of which presents a seat adapted to cooperate with said float, and means for moving said float against said seat including a rod, a valve member on said rod and a seat to cooperate with said member.

31. An instrument of the class described comprising communicating wells for the re ception of a fluid, means to admit pressures to the wells, a float in 'one well, a ported seat above the float adapted to cooperate therewith to close the well, a tube opening from the well, said float having a depending stem guided by said tube, a member enterin said tube from the exterior and arranges for adjustment against the stem to seat said float, an enlargement on said member and a seat adapted to cooperate with the enlargement to seal the tube.

32. An instrument of the class described comprisin comunicating wells for the reception o a fluid, means to admit pressures to the Wells, a float in one Well, a ported seat above the float adapted to cooperate therewith to close the well, a tube opening from the Well, said float having a depending stem guided by said tube, a bushing at the end of saidtube, a rod passing through said bushing, and adjustable against said stem to seat the float, a packing for the rod and an enlargement on the rod adapted to be seated against the bushing inwardly thereof to seal the tube.

In testimony whereof, I name to this specification.

EDGAR H. BRISTOL.

have signed my Certificate of Correction.

It is hereby certified that upon the application of Edgar H. provement in Pressure Gauges, requiring correction as follows: Page form to the record of the case in Signed and sealed this 24th [snub] in Letters Patent No. 1,592,415,

Bristol, of Foxboro, an error appears in 5, line 1, claim 12, after strike out the comma and insert instead the word comp rising,- Letters Patent should be read with this correction therein that the Patent Office.

day ofAugust,

granted July 13, 1Q26, Massachusetts, for an 1 mthe printed specification the word well" and that the said the same may con- M. J. MOORE, Acting Uommiasimwr of Patents.-

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,592,415, granted July 13, 1926, upon the application of Edgar H. Bristol, of Foxboro, Massachusetts, for an improvement in Presure Gauges. rm error appears in the printed specification requiring correction as follows: Page 5, line 1, claim 12, after the word well strike out .the comma and insert instead the word commigmg; and that the said Letters Patent should be read with this correction therein that the same may confol-1p to the record of the ease in the Patent Oflice.

Sngned and sealed this 24th day of-August, A. D. 1926.

[m] M. J. MOORE,

Acting Uommiasiorwr of Patents. 

